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Q7LZG2 (PA2T_OXYSC) Reviewed, UniProtKB/Swiss-Prot

Last modified February 19, 2014. Version 49. Feed History...

Clusters with 100%, 90%, 50% identity | Documents (1) | Third-party data text xml rdf/xml gff fasta
to top of pageNames·Attributes·General annotation·Ontologies·Sequence annotation·Sequences·References·Web links·Cross-refs·Entry info·DocumentsCustomize order

Names and origin

Protein namesRecommended name:
Phospholipase A2 taicatoxin

Short name=TCX
Short name=svPLA2
EC=3.1.1.4
Alternative name(s):
Phosphatidylcholine 2-acylhydrolase
OrganismOxyuranus scutellatus scutellatus (Australian taipan) (Coastal taipan)
Taxonomic identifier8667 [NCBI]
Taxonomic lineageEukaryotaMetazoaChordataCraniataVertebrataEuteleostomiLepidosauriaSquamataBifurcataUnidentataEpisquamataToxicoferaSerpentesColubroideaElapidaeAcanthophiinaeOxyuranus

Protein attributes

Sequence length27 AA.
Sequence statusFragment.
Protein existenceEvidence at protein level

General annotation (Comments)

Function

Heterotrimer: blocks the voltage-dependent L-type calcium channels from the heart, and the small conductance calcium-activated potassium channels in the chromaffin cells and in the brain. Is very toxic to mice. Ref.1 Ref.2 Ref.3 Ref.4 Ref.5

Monomer: Snake venom phospholipase A2 (PLA2) that has neurotoxic activities. Voltage-dependently affects ionic currents in chick (Gallus domesticus) dorsal root ganglion cells. PLA2 catalyzes the calcium-dependent hydrolysis of the 2-acyl groups in 3-sn-phosphoglycerides. Ref.1 Ref.2 Ref.3 Ref.4 Ref.5

Catalytic activity

Phosphatidylcholine + H2O = 1-acylglycerophosphocholine + a carboxylate.

Cofactor

Binds 1 calcium ion By similarity.

Subunit structure

Heterotrimer composed of an alpha-neurotoxin-like peptide of 8 kDa (AC P0CJ35), this neurotoxic phospholipase of 16 kDa and a serine protease inhibitor of 7 kDa (AC B7S4N9) at an approximate stoichiometry of 1:1:4; non-covalently linked. Ref.2

Subcellular location

Secreted Ref.1 Ref.2.

Tissue specificity

Expressed by the venom gland. Ref.1 Ref.2

Post-translational modification

Contains 7 disulfide bonds By similarity.

Toxic dose

LD50 of the monomer is 500 µg/kg to mice. Ref.1 Ref.2

LD50 of the heterotrimer is 50-100 µg/kg to mice. Ref.1 Ref.2

Sequence similarities

Belongs to the phospholipase A2 family. Group I subfamily.

Ontologies

Keywords
   Biological processLipid degradation
Lipid metabolism
   Cellular componentSecreted
   LigandCalcium
Metal-binding
   Molecular functionHydrolase
Ion channel impairing toxin
Neurotoxin
Potassium channel impairing toxin
Toxin
   PTMDisulfide bond
   Technical termDirect protein sequencing
Gene Ontology (GO)
   Biological_processlipid catabolic process

Inferred from electronic annotation. Source: UniProtKB-KW

   Cellular_componentextracellular region

Inferred from electronic annotation. Source: UniProtKB-SubCell

   Molecular_functionmetal ion binding

Inferred from electronic annotation. Source: UniProtKB-KW

phospholipase A2 activity

Inferred from electronic annotation. Source: UniProtKB-EC

Complete GO annotation...

Sequence annotation (Features)

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifier

Molecule processing

Chain‹1 – ›27›27Phospholipase A2 taicatoxin
PRO_0000408515

Experimental info

Non-terminal residue11
Non-terminal residue271

Sequences

Sequence LengthMass (Da)Tools
Q7LZG2 [UniParc].

Last modified December 15, 2003. Version 1.
Checksum: A74F18ACB843133C

FASTA272,901
        10         20 
NLAQFGFMIR CANGGSRSAL DYADYGC 

« Hide

References

[1]"Anionic currents of chick sensory neurons are affected by a phospholipase A2 purified from the venom of the taipan snake."
Possani L.D., Mochca-Morales J., Amezcua J., Martin B.M., Prestipino G., Nobile M.
Biochim. Biophys. Acta 1134:210-216(1992) [PubMed] [Europe PMC] [Abstract]
Cited for: PROTEIN SEQUENCE, FUNCTION, SUBCELLULAR LOCATION, TISSUE SPECIFICITY, LETHAL DOSE.
Tissue: Venom.
[2]"Isolation and physiological characterization of taicatoxin, a complex toxin with specific effects on calcium channels."
Possani L.D., Martin B.M., Yatani A., Mochca-Morales J., Zamudio F.Z., Gurrola G.B., Brown A.M.
Toxicon 30:1343-1364(1992) [PubMed] [Europe PMC] [Abstract]
Cited for: PROTEIN SEQUENCE, FUNCTION, SUBUNIT, SUBCELLULAR LOCATION, TISSUE SPECIFICITY, LETHAL DOSE.
Tissue: Venom.
[3]"Effect of TaiCatoxin (TCX) on the electrophysiological, mechanical and biochemical characteristics of spontaneously beating ventricular cardiomyocytes."
Fantini E., Athias P., Tirosh R., Pinson A.
Mol. Cell. Biochem. 160:61-66(1996) [PubMed] [Europe PMC] [Abstract]
Cited for: FUNCTION.
[4]"A novel small conductance Ca2+-activated K+ channel blocker from Oxyuranus scutellatus taipan venom. Re-evaluation of taicatoxin as a selective Ca2+ channel probe."
Doorty K.B., Bevan S., Wadsworth J.D.F., Strong P.N.
J. Biol. Chem. 272:19925-19930(1997) [PubMed] [Europe PMC] [Abstract]
Cited for: FUNCTION.
[5]"Taicatoxin inhibits the calcium-dependent slow motility of mammalian outer hair cells."
Su M.-C., Lee S.-Y., Tan C.-T., Su C.-C., Li S.-Y., Lin R.-H., Hung C.-C., Lin M.-J.
Hear. Res. 203:172-179(2005) [PubMed] [Europe PMC] [Abstract]
Cited for: FUNCTION.

Web resources

Wikipedia

Taicatoxin entry

Cross-references

Sequence databases

PIRA34280.
S21101.

3D structure databases

ModBaseSearch...
MobiDBSearch...

Protocols and materials databases

StructuralBiologyKnowledgebaseSearch...

Family and domain databases

InterProIPR016090. PLipase_A2_dom.
[Graphical view]
PfamPF00068. Phospholip_A2_1. 1 hit.
[Graphical view]
SUPFAMSSF48619. SSF48619. 1 hit.
ProtoNetSearch...

Entry information

Entry namePA2T_OXYSC
AccessionPrimary (citable) accession number: Q7LZG2
Entry history
Integrated into UniProtKB/Swiss-Prot: May 31, 2011
Last sequence update: December 15, 2003
Last modified: February 19, 2014
This is version 49 of the entry and version 1 of the sequence. [Complete history]
Entry statusReviewed (UniProtKB/Swiss-Prot)
Annotation programAnimal Toxin Annotation Program
Annotation programChordata Protein Annotation Program

Relevant documents

SIMILARITY comments

Index of protein domains and families